3GPP (3rd Generation Partnership Project) is a project to discuss/create specifications of a mobile communication system based on networks of evolved W-CDMA (Wideband-Code Division Multiple Access) and GSM (Global System for Mobile Communications). In 3GPP, the W-CDMA system has been standardized as the third generation cellular mobile communication system and its services have been launched sequentially. Further, HSDPA (High-speed Downlink Packet Access) with the communication speed further increased has also been standardized and its services are launched. In 3GPP, the evolution of the third generation radio access technology (hereinafter, referred to as “LTE (Long Term Evolution)” or “SUTRA (Evolved Universal Terrestrial Radio Access)”) and a mobile communication system (hereinafter, referred to as “LTE-A (Long Term Evolution-Advanced” or “Advanced-EUTRA”) that utilizes a wider system bandwidth to achieve faster data transmission and reception are discussed.
As a communication system in LTE, an OFDMA (Orthogonal Frequency Division Multiple Access) system and a SC-FDMA (Single Carrier-Frequency Division Multiple Access) system that use subcarriers orthogonal to each other to perform user multiplexing are discussed. Meanwhile, in a downlink, the OFDMA system, which is a multi-carrier communication system, is proposed; in an uplink, the SC-FDMA system, which is a single-carrier communication system, is proposed.
On the other hand, it is proposed that, as a communication system in LTE-A, in a downlink, the OFDMA system be introduced, and, in an uplink, in addition to the SC-FDMA system, which is a single-carrier communication system, the OFDMA system, which is a multi-carrier communication system, and a Clustered-SC-FDMA (Clustered-Single Carrier-Frequency Domain Multiple Access, also called DFT-S-OFDM with Spectrum Division Control) system be introduced (non-patent documents 1 and 2). The SC-FDMA system examined as an uplink communication system in LTE or LTE-A has the feature of lowering a PAPR (Peak to Average Power Ratio) when transmitting data.
It is also proposed that although a frequency band used in a general mobile communication system is continuous, in LTE-A, multiple continuous/non-continuous frequency bands (hereinafter, referred to as a “carrier component” or “component carrier”) be used in a composite manner and utilized (spectrum aggregation or carrier aggregation) as one wider frequency band (wider system band). Moreover, it is proposed that, in order to use more flexibly a frequency band assigned to a mobile communication system, a frequency band used in downlink communication and a frequency band used in uplink communication have different frequency bandwidths (non-patent documents 3 and 4).    Non-patent document 1: “UL Access Scheme for LTE-Advanced”, 3GPP TSG RAN WG1 Meeting #53-bis, R1-082365, Jun. 30-Jul. 4, 2008.    Non-patent document 2: “Consideration on Multicarrier Transmission scheme for LTE Adv uplink”, 3GPP TSG RAN WG1 Meeting #53-bis, R1-082398, Jun. 30-Jul. 4, 2008.    Non-patent document 3: “Proposals for LTE-Advanced Technologies”, 3GPP TSG RAN WG1 Meeting #53-bis, R1-082575, Jun. 30-Jul. 4, 2008.    Non-patent document 4: “Carrier aggregation in LTE-Advanced”, 3GPP TSG RAN WG1 Meeting #53-bis, R1-082468, Jun. 30-Jul. 4, 2008.